Automatic tensioning device for looms



A. W. CAMPBELL AUTOMATIC TENSIONING DEVICE FOR LOOMS Filed June 50, 1958 Feb. 7,1961

FlG/Z FIG. 7

R m.. ml. WE B P M 6 A c c H w A MB n 28 FIG. 8

ATTORNEY United States Patent AUTOMATIC TENSIONING DEVICE FOR LOOMS Archie W. Campbell, Rte. 4, Box 262, Kannapolis, N.C.

Filed June 30, 1958, Ser. No. 745,504

This invention relates to the weaving of cloth, wire mesh, and other materials, and equipment employed including a loom and a shuttle through which the thread is fed as it moves in its path during the weaving operation.

The invention relates particularly to the tension upon the thread and the mechanism by which the tension is maintained between the thread and the shuttle which plays such an important part in the appearance, quality and other significant characteristics of the finished product.

With prior weaving equipment considerable difiiculty has been experienced in the manufacture of cloth, wire mesh, and other material. The creation'of loops during the stoppage of the shuttle at the end of its travel has resulted in the weaving of the threadsunevenly and the creation of a defective end product. Efforts have been made to overcome the difiiculties and provide a solution for this problem, however the anticipated solution has been inadequate, has complicated the situation, or rendered the same more complex.

It is an object of the invention to provide simple, inexpensive and efiective means for overcoming the problem indicated and to provide a shuttle with automatic thread tensioning means which will effectively prevent looping of the thread as the shuttle reaches the end of its travel and an improved and satisfactory end product will result.

Another object of the invention is to provide a shuttle with simple and efiective tensioning mechanism in the form of a pivotally mounted or suspended gravity controlled weight above the thread, which will rest upon the thread and maintain the necessary tension thereon.

Other objects and advantages of the invention will be come apparent from the following description taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a perspective illustrating one application of the invention to a conventional shuttle;

Fig. 2, an enlarged fragmentary top plan view of the end of the shuttle eye containing the tensioning device of this invention;

Fig. 3, a section on the line 3-3 of Fig. 2;

Fig. 4, a modified form of the weight employed in the automatic tensioning device of the present invention;

Fig. 5, a view similar to Fig. 2 of a modified form of the device;

Fig. 6, a section on the line 6-6 of Fig. 5;

Fig. 7, a view similar to Fig. 2 of a modified form of the device; and

Fig. 8, a section on the line 8-8 of Fig. 7.

Briefly stated, the invention is the application of a thread tensioning device located in close proximity to the eye of a conventional shuttle to prevent the thread from looping as the shuttle reaches the end of its travel. The tensioning device is in the form of a gravity controlled weight pivotally suspended either from within the confines of the shuttle eye or behind the same, or from an independent U-shaped bracket. The gravity controlled weight is positioned above the thread and is of a configuration such that when the eye is threaded, the thread will slide ice over the top of the weight and assume a position under such weight. When tension is applied to the thread during the weaving operation, the thread will engage the bottom of the weight and thus raise the weight. As soon as the shuttle reaches the end of a course, the thread will no longer be under tension but will sag and the weight will fall by gravity to exert pressure on the thread and prevent the formation of a loop.

With continued reference to the drawing the thread tensioning device of the present invention is embodied in a shuttle 10 of conventional construction having an elongated bobbin receiving portion or opening 11 in which a bobbin 12 is adapted to be contained.

From the bobbin 12 the thread 13 is dispensed through an eye 14 held in place by an attaching bolt 14 in the normal functioning of the shuttle and loom in the usual weaving operation.

With the above mentioned structure, when the shuttle 10 reaches the end of its travel, the tension on the thread 13 will be interrupted until the shuttle begins its travel in the reverse direction. This interruption of the tension on the thread is undesirable since the momentum of the thread tends to cause the thread to form a loop and consequently causes an imperfection in the production of the fabric. In order to overcome this difficulty and maintain tension on the thread, an automatic gravity actuated thread tensioning device is provided and this tensioning device is designed to maintain a tension on the thread at the end of travel of the shuttle in one direction before it begins its travel in the opposite direction.

One way in which the automatic gravity actuated thread tensioning device may be embodied in a physical structure is illustrated in Figs. 1, 2 and 3 wherein the rear portion of the eye 14 has been removed and an upper portion 15 cut out to leave an upstanding bracket 16 pro- .vided with a threaded opening 17 for the reception of an externally threaded supporting screw 18 on which is mounted a coil type gravity actuated swinging arm or lever 19 having a pair of supporting arms 20 with mounting portions disposed about the screw 18 and having a thread engaging portion.

The lever 19 is normally in the direct path of movement of the thread 13 and when the thread is being dispensed it extends beneath the lever 19 and holds the same slightly elevated. When the shuttle comes to the end of its travel in one direction the thread which passes through the shuttle eye is relieved of its tension and the weight will force it down and maintain the tension thereon.

Instead of the coil type gravity actuated swinging arm or lever tensioning device as illustrated in Figs. 1, 2 and 3 a solid type tensioning device 21 as illustrated in Fig. 4 may be employed. This device has a pivot opening 22 and a weighted or latch portion 23 spaced therefrom and with a notch 24 in which the thread is received. The operation of this form of tensioning device is similar to that of the structure of Figs. 1, 2 and 3 A still further modified type of tensioning device may be employed as illustrated in Figs. 5 and 6 wherein the rear portion of the shuttle eye has been detached and removed and a pivot screw 25 threaded into the retained rear portion of the shuttle eye. On this screw 25 is mounted a gravity actuated swingable weighted substantially C-shaped arm or lever 26 with an extended bearing portion 27. The portion of the C-shaped arm away from the pivot is adapted to curl about the thread 13.

A further modification of the thread tensioning device is disclosed in Figs. 7 and 8 in which a unitary device is provided in the form of a U-shaped bracket 28 having outwardly turned flanged extremities 29 adapted to be secured in the shuttle by means of fasteners 30. The bobbin opening in the shuttle may be enlarged to receive the bracket or the bracket may be made of relatively thin '3 material so that substantially no space is required for it.

A swinging arm or lever 31 is disposed in a slot 32 in the U-shaped bracket 28 and mounted thereon by a pivot pin'33, such arm having a notch34 for the reception of the thread 13.

With each type of the devices described, the operation is the same to the degree that a portion of the device under the influence of gravity overlies the thread and is raised when the thread is under tension and lowers by gravity when the tension is relieved to maintain tension on the thread.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated in the drawing and described in the specification, butonly as indicated in the accompanying claims.

What is claimed is:

1. The combination of a shuttle for a loom and a tensioning device, said tensioning device comprising a pivotal mounting secured to said shuttle above the path or" the thread leading from said bobbin outwardly from said shuttle, a gravity-actuated swinging lever including two arms freely-pivotally secured to said pivotal mounting and extending downwardly therefrom, and a coil portion connected to the lower ends of said arms, said coil portion having its external surface engaging the thread extending beneath said tensioning device, whereby said coil portion will' be elevated by the thread when the latter is under tension while being dispensed and will move by gravity downwardly to take up slack and continue by its weight to bear upon the thread when the tension thereon is eased.

2. The combination of a shuttle for a loom and a tensioning device, said shuttle having an elongated bobbinreceiving portion and a cavity communicating therewith whereby the thread can be led from the bobbin through said cavity from said shuttle, said cavity being open to the exterior of said shuttle, said tensioning device comprising a pivotally suspended body having a mounting portion and a thread-engaging portion, said mounting portion being pivotally secured to said shuttle at one side of said cavity above the path of the thread from the bobbin, the pivotal axis of said mounting portion of said body being substantially parallel to the length of said shuttle, said thread-engaging portion being disposed partially over the width of said cavity, said thread-engaging portion being located in the path of travel of the thread and being of such proportions and weight that it will be elevated by the thread when the latter is under tension while being dispensed and such thread engaging portion will be moved by gravity downwardly to take up slack and continue by its weight to bear upon the thread when the tension there on is eased, said thread-engaging portion having its external surface engageable with the thread over a relatively small area.

3. The invention as set forth in claim 2 wherein said body isa gravity-actuated swinging lever including an upper mounting portion having an aperture therethrough and a depending arm having a notch in its lower surface, said notch being engageablewith'a thread located beneath said tensioning device, a supporting screw extending from the shuttle body through the aperture in said lever for pivotally supporting said lever.

4. The invention as set'forth in claim 2 wherein said body is a gravity-actuated'swinging lever including an upper mounting portion having an aperture formed therein and a depending C-shaped portion the external surface of which is engageable with the thread, and including a pivotal mounting secured to said shuttle and extending into said aperture in said lever.

5. The invention as set forth in claim 2 wherein the tensio-ning device includes a U-shaped bracket mounted in said shuttle and having its open end uppermost, said body being a gravity-actuated swinging lever having one end freely pivotally secured to one end of said U-shaped bracket, said'lever depending from said pivot and having a free end with a notch in its external surface for receiving the thread beneath said tensi'oning device, whereby said notched free end will be elevatedby the thread when the latter is under tension while being dispensed and will be moved by gravity downwardly to take up slack and continue by its weight to bear on the thread when the tension is eased,

References Cited in the file of this patent UNITED STATES PATENTS 479,084 Bardsley July 19, 1892 501,781 Hamblin July 18, 1893 1,307,336 Barton et a1. June 24, 1919 1,947,133 Lundgren Feb. 13, 1934 FOREIGN PATENTS 240,704 Great Britain "Oct. 8, 1925 

